Light-Triggered Release from Pickering Emulsions Stabilized by TiO2 Nanoparticles with Tailored Wettability

In this work, a new strategy for developing light-triggered Pickering emulsions as smart soft vehicles for on-demand release is proposed. Initially, UV-induced tailored wettability allows anchoring of TiO2 nanoparticles at the interface to prepare stable water in oil emulsions. Such emulsions show the efficacy of microencapsulation and controlled release by demulsification due to the hydrophilic conversion of the TiO2 nanoparticles using a noninvasive light irradiation trigger. A molecule of interest is selected as a model cargo to quantitatively evaluate the as-prepared Pickering emulsions for their encapsulation and release behaviors. Moreover, light-responsive emulsion destabilization mechanism is studied as a function of particle concentration, light wavelength, and light intensity, respectively, determined by drop diameter evolution and droplet coalescence kinetics plots. For consideration of application in life sciences, Pickering emulsions sensitive to visible light are also established based on nitrogen doping of TiO2 nanoparticle emulsifiers.